Devices and methods for flipping a sheet with blowing assistance

ABSTRACT

A rotary sheet flipper may not properly flip certain types of sheets, for example sheets with a low beam strength. The invention relates to devices and methods for flipping a sheet with blowing assistance. According to various aspects of the invention, devices and methods for flipping a sheet are provided comprising receiving an end of the sheet, flipping the end with the sheet otherwise unrestrained; and blowing the sheet to assist flipping the sheet. Numerous variations and modifications are evident in light of the description provided herein.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a 111A application of Provisional Application Ser. No.60/581,548, filed Jun. 21, 2004, entitled DEVICES AND METHODS FORFLIPPING A SHEET WITH BLOWING ASSISTANCE by David J. Laluk, et al.

BACKGROUND OF THE INVENTION

A rotary sheet flipper may not properly flip certain types of sheets,for example sheets with a low beam strength. The invention relates todevices and methods for flipping a sheet with blowing assistance.

SUMMARY OF THE INVENTION

According to various aspects of the invention, devices and methods forflipping a sheet are provided comprising receiving an end of the sheet,flipping the end with the sheet otherwise unrestrained; and blowing thesheet to assist flipping the sheet. Numerous variations andmodifications are evident in light of the description provided herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 presents a schematic side view of an apparatus according to oneaspect of the invention.

FIG. 2 presents a partial cross-sectional view taken along line 2-2 ofFIG. 1.

FIG. 3 presents a partial cross-sectional view of the apparatus 100taken along line 3-3 of FIG. 1.

FIG. 4 presents a partial cross-sectional view of the apparatus 100 isprovided taken along line 4-4 of FIG. 2.

FIGS. 5-8 present the same partial cross-section as FIG. 4, but atdifferent stages of operation so certain components are in differentpositions depending upon the stage of the sequence.

FIGS. 9 and 10 present a schematic end view and a schematic front view,respectively, of one embodiment of a blowing source and mount.

FIGS. 11 and 12 present a schematic end view and a schematic front view,respectively, of another embodiment of a blowing source and mount.

FIG. 13 presents a exemplary blower output curve for a blower that maybe implemented in the practice of the invention.

FIG. 14 presents a top view of one embodiment of a tamper, side plate,and stack, with portions broken away.

DETAILED DESCRIPTION OF THE INVENTION

Various aspects of the invention are now described with reference to thedrawings, which are not drawn to any particular scale, and wherein likecomponents in the numerous views are numbered alike. Referring nowspecifically to FIGS. 1 and 2, a sheet processing apparatus 100 ispresented according to one aspect of the invention. FIG. 1 presents aschematic side view of the apparatus 100, and FIG. 2 presents a partialcross-sectional view taken along line 2-2 of FIG. 1. Apparatus 100comprises a sheet handling device 102 for flipping a sheet 104. Thesheet 104 has an end 106. The sheet handling device 102 comprises arotary sheet flipper 108 that comprises a sheet holder 110 that receivesthe sheet end 106 and flips the sheet end 106 with the sheet 104otherwise unrestrained. A blowing source 112 is oriented to assistflipping the sheet 104.

The apparatus 100 of FIG. 1 is a stacker, for purposes of illustration,but the invention is not limited to use in a stacker. If configured asstacker, the apparatus 100 places the sheet 104 on a stack of sheets105. The apparatus 100 comprises a sheet transport path 114 thatimplements driven nips (not shown), for example, to move the sheet 104along the transport path 114, as indicated by arrow 116. An example of adriven nip is a pair of opposing rollers, one of the rollers beingdriven. Such mechanisms are very well known in the sheet transport art.

Apparatus 100 also comprises a diverter 118 that alternatively directsthe sheet 104 to transport path 120, or transport path 122, dependingupon the position of the diverter 118. In FIG. 1, the diverter ispositioned to direct the sheet 104 to the transport path 122. Transportpath 122 is directed to the rotary sheet flipper 108, and transport path120 is directed to exit the right side of the apparatus, for furthersheet processing by another apparatus for example. The sheet 104 may bedirected to the transport path 120 by rotating the diverter 118counter-clockwise around a pivot 124. The transport path may be providedwith driven nips 126 and 128.

FIG. 3 presents a partial cross-sectional view of the apparatus 100taken along line 3-3 of FIG. 1. An air source 130 is in fluidcommunication with the blowing source 112 via a hose or tube 132. Theair source 130 may be any device suitable for developing air movement,for example a blower, fan, or a compressed air source (a compressor).One, two, or more blowing sources 112 may be provided, and more than onehose 132 may be provided to supply multiple blowing sources. Awye-connection 134 may be provided to split the output from the airsource 130 between two blowing sources 112. Other plumbing arrangementsmay also be implemented, such as one or more manifolds. A regulator 136may be provided to adjust the flow and/or pressure applied to theblowing source 112, for example a bleed valve that vents some of theflow to ambient. The regulator 136 may be adjustable to permit tuningthe blowing source 112 for sheets having particular properties.Alternatively, the air source motor may be regulated to provide adesired flow, for example by regulating DC voltage supply to a DC airsource motor. The air source 130 and/or regulator 136 may be mountedanywhere on the apparatus 100 where convenient, particularly whereaccess is available to adjust the regulator 136. The air source 130 isshown mounted on a side panel of the apparatus 100. A more convenientlocation may be on the back of the apparatus. The air source 130 maybemounted immediately adjacent the blowing source 112, in the area of therotary sheet flipper 108 for example, thereby eliminating most or all ofthe interconnecting hose.

Referring again to FIGS. 1 and 2, the sheet holder 110 is configured asa wheel mounted on a shaft 138, the wheel comprising a tongue 140 thatdefines a slot 142 that receives the sheet end 106. The exemplary rotarysheet flipper 108 presented in the drawings comprises two sheet holders110 each configured as a wheel and each having two tongues 140diametrically opposed on each wheel.

FIG. 4 presents a partial cross-sectional view of the apparatus 100taken along line 4-4 of FIG. 2. Referring now to FIGS. 2 and 4, thesheet handling device 102 comprises a tamper 144 that traps the sheetend 106 after flipping, and a side plate 214. The sheet holder 110comprises a cam 146. The tamper 144 comprises a tamper shaft 148, atamper arm 150 mounted to the tamper shaft 148 that engages the sheetend 106, and a cam arm 152 mounted to the tamper shaft 148 thatinteracts with the cam 146.

According to a further aspect of the invention, a sheet flipping methodis provided comprising receiving the sheet end 106, flipping the sheetend 106 with the sheet 104 otherwise unrestrained, and blowing the sheet104 to assist flipping the sheet 104. The method may comprise placingthe sheet 104 on a stack of sheets 105. The blowing may also be orientedand re-oriented in order to adjust the sheet handling device 102 forprocessing of sheets 104 having different characteristics. The sheet end106 may be trapped after flipping. The method may comprise placing thesheet 104 on a stack of sheets 105 and trapping the sheet end 106 on thestack of sheets 105 after flipping.

FIGS. 5-8 present the same partial cross-section as FIG. 4, but atdifferent stages of operation of the sheet handling device 102 socertain components are in different positions depending upon the stageof the sequence. Operation of the sheet handling device 102 will now bediscussed in more detail with reference to FIGS. 4-8. Blowing, asindicated by arrows 154 may be initiated by powering the air source 130at the same time the main drive for the apparatus is powered. Referringnow specifically to FIG. 4, the sheet 104 is driven by the nip 128 asindicated by arrow 156 so that the sheet 104, and more specifically thesheet end 106 is received by the sheet holder 110 within the slot (142of FIG. 1) defined by the tongue 140. Referring now to FIG. 5, acounter-clockwise rotation of the sheet holder 110 is initiated by amotor as the nip 128 continues to drive the sheet 104. One of the cams146 interacts with the cam arm 152, which causes the tamper 144 torotate clockwise and lift the tamper arm 150 from the stack of sheets105. At this point of the rotation of the sheet holder 110, the sheet104 is approximately aligned with the right edge of the stack 105, andthe sheet end 106 is positioned beneath the tamper arm 150. Rotation ofthe sheet holder 110 continues until the cam 146 passes the end of thecam arm 152 thus releasing the tamper 144 to rotate counter-clockwiseunder a spring load, or other force such as a solenoid or the force ofgravity for example, until the tamper arm 150 rests on the sheet end 106so that the sheet end 106 is gripped between the tamper arm 150 and thesheet stack 105, as is shown in FIG. 6. The tamper 144 may be damped bya damper, particularly if the tamper arm 150 tends to bounce. A quickgripping of the sheet end 106 after the sheet holder 110 releases it isdesirable so that the blowing source 112 does not have an opportunity toblow the entire sheet 104 away. Gripping in the range of 15-60milliseconds from the time the leading edge of the sheet 104 firststrikes the side plate 214 (FIG. 6) is believed to be satisfactory. Allor part of the tongue 140, for example about one-third of it, may bedisposed between the sheet end 106 and the stack of sheets 105 when thetamper first contacts the sheet end 106 and traps it. Rotation of thesheet holder 110 continues until the tongue 140 is removed, and thenstops. Referring now to FIG. 7, the nip 128 continues to drive the sheet104, which forms a loop moving to the left as indicated by arrow 158.Eventually the end of the sheet 104 opposite the sheet end 106 exits thenip 128 and the transport 122, as shown in FIG. 8. The blowing providedby the blowing source 112 urges continuing movement of the balance ofthe sheet, as indicated by arrow 156, so that ultimately the sheet liesflat on the stack 105. The sheet holder 110 maybe rotated into theposition shown in FIG. 4, at an appropriate time, in order to repeat thecycle for another sheet.

Without the blowing provided by the blowing source 112, sheets havingcertain properties, particularly sheets having a low beam strength, tendto remain in the looped position on the top of the stack 105. Stateddifferently, the motion indicated in FIG. 8 does not occur the sheetremains looped and does not open. The next sheet is deposited andseveral sheets may be deposited in this condition. The looped sheet isdamaged and the stack is altered in an undesirable manner that mayrender the stacker inoperable until the looped sheet (or sheets) iscleared.

Referring again to FIG. 1, the sheet stack 105 rests on a tray 160. Thetray may be removable, and may be provided with wheels (not shown) tofacilitate transporting it from one location to another on a shop floor.The elevation of the tray is controlled by multiple chain drives 162, orother suitable mechanism for controlling the elevation of a tray in astacker. In one embodiment, four chain drives 162 are provided, one ateach corner of the tray 160. Each chain drive 162 comprises a sprocket164 and a chain 166. The chain drives are controlled so that the tray160 lowers as sheets are added to the sheet stack 105 such that the topof the sheet stack 105 remains at an approximately constant location.

Referring now to FIGS. 9 and 10, a schematic end view and a schematicfront view, respectively, of the blowing source 112 and mount 113 arepresented. Mount 113 comprises a bracket 168. A clamp 170 holds a tube172 in place and is mounted to the bracket 168 by a fastener 174.Another fastener 176 mounts the bracket 168 in place within theapparatus 100, as shown in FIGS. 2 and 4-8. The tube. 172 is connectedto the hose 132 of FIGS. 1 and 3. Referring again to FIGS. 9 and 10, andaccording to one aspect of the invention, the blowing source 112 may beoriented by moving it in a first direction 178, a second direction 180,and/or at least a third direction 182 (an additional direction 184 isalso indicated). The blowing source 112 may also be oriented by rotatingit, for example, about fastener axis 186 or fastener axis 188. Theblowing source may be oriented by translating it and rotating it. Themount 113 may be made adjustable to permit orienting and re-orientatingthe blowing source 112.

Referring now to FIGS. 11 and 12, a schematic side view and a schematicfront view, respectively, of a blowing source 190 and mount 192 arepresented according to another embodiment of the invention. Mount 192.comprises a bracket 198. The blowing source 190 comprises a tube 194perforated with an array of holes 196. The tube 172 is connected to thehose of FIGS. 1 and 3. Referring again to FIGS. 11 and 12, a clamp 200holds the tube 194 in place and is mounted to the bracket 198 by thefastener 174. The fastener 176 mounts the bracket 168 in place withinthe apparatus 100. The blowing source 190 and mount 192 of FIGS. 11 and12 may be a direct substitute for the blowing source 112 and mount 113of FIGS. 9 and 10. A mirror image arrangement may be substituted on theother side of the rotary sheet flipper 108 (on the left in FIG. 2). Asshown in FIG. 2, the rotary sheet flipper 108 is rotatable about an axisof rotation 202. Referring again to FIGS. 11 and 12, the tube 194 has alongitudinal axis 204, and may be parallel to the axis of rotation 202of the rotary sheet flipper 108.

The blowing source 190 may be oriented and re-oriented as previouslydescribed with reference to blowing source 112. Further additionaldirections of adjustment 206, 208 and more may be implemented, asdesired. The blowing source 190 may be rotated about the longitudinalaxis 204, as indicated by arrows 210. The array of holes 196 may bedeflected toward the stack of sheets 105, as shown in FIG. 11.

The holes 196 may be aligned in one or more lines. Two rows of holes196, for example, may be implemented. One or more rows of holes 196 maybe deflected toward the stack of sheets 105, or just one row out ofmultiple rows of holes 196 may be deflected toward the stack or sheets105. The holes 196 need not be aligned in lines since any pattern thatachieves the result described herein may be implemented in the practiceof the invention.

In a certain embodiment, the tube 194 is copper with an outside diameterof 0.60 inches and an inside diameter of 0.57 inches (standard ½″ copperpipe). There are four (4) holes 196, each hole 196 having a diameter of0.11 inch, two holes 196 on either side of the mount 192, aligned in astraight line and deflected toward the stack of sheets 105, as shown inFIG. 11. Two such mirror arrangements were provided, one on either sideof a rotary sheet flipper 108, powered by an Ametek® blower part number119350-00 that generates the curve shown in FIG. 13 (according tomanufacturer's specifications), available from Ametek, Kent, Ohio,U.S.A. An adjustable bleed regulator 136 was provided and operated fromfull close (no bleed) to full open (full bleed) depending upon thetuning desired.

Referring now to FIG. 14, a top view of one embodiment of the tamper144, side plate 214 (FIG. 6), and stack 105, with portions broken awayis presented. The tamper 144 may comprise two L-shaped tamper arms 150disposed on either side of a center T-shaped tamper arm 151. The tamperarms 150 and 151 are firmly fixed to the tamper shaft 148 of FIGS. 2 and3-8.

Referring again to FIG. 1, a controller 212 is provided to controloperation of the apparatus 100. The controller 212 may implementsoftware, hardware, and/or firmware. The controller may be configuredaccording to methods and practices known in the art.

In view of the wide variety of embodiments to which the principles ofthe present invention can be applied, it should be understood that theillustrated embodiments are exemplary only, and should not be taken aslimiting the scope of the present invention.

The claims should not be read as limited to the described order orelements unless stated to that effect. In addition, use of the term“means” in any claim is intended to invoke 35 U.S.C. §112, paragraph 6,and any claim without the word “means” is not so intended.

Although the invention has been described and illustrated with referenceto specific illustrative embodiments thereof, it is not intended thatthe invention be limited to those illustrative embodiments. Thoseskilled in the art will recognize that variations and modifications canbe made without departing from the true scope and spirit of theinvention as defined by the claims that follow. It is therefore intendedto include within the invention all such variations and modifications asfall within the scope of the appended claims and equivalents thereof.

Parts list

-   100 sheet processing apparatus-   102 sheet handling device-   104 sheet-   105 stack of sheets-   106 end-   108 rotary sheet flipper-   110 sheet holder-   112 blowing source-   113 mount-   114 transport path-   116 arrow-   118 diverter-   120 transport path-   122 transport path-   124 pivot-   126 and 128 driven nips-   130 air source-   132 hose-   134 wye-connection-   136 regulator-   138 shaft-   140 tongue-   142 slot-   144 tamper-   146 cam-   148 tamper shaft-   150 tamper arm-   151 t-shaped tamper arm-   152 cam arm-   154 arrows-   156 arrow-   158 arrow-   160 tray-   162 chain drives-   164 sprocket-   166 chain-   168 bracket-   170 clamp-   172 tube-   174 fastener-   176 fastener-   178 first direction-   180 a second direction-   182 third direction-   184 additional direction-   186 fastener axis of rotation-   188 fastener axis of rotation-   190 blowing source-   192 amount-   194 tube-   196 array of holes-   198 bracket-   200 clamp-   202 axis of rotation-   204 longitudinal axis-   206, 208 further directions of adjustment-   210 arrows-   212 controller-   214 side plate

1. A sheet handling device for flipping a sheet comprising a sheet end,comprising: a rotary sheet flipper comprising a sheet holder thatreceives the sheet end and flips the sheet end with the sheet otherwiseunrestrained; and, a blowing source oriented to assist flipping thesheet.
 2. The device of claim 1, the sheet holder comprising a wheelmounted on a shaft, the wheel comprising a tongue that defines a slotthat receives the sheet end.
 3. The device of claim 1, comprising anadjustable mount that permits re-orientating the blowing source.
 4. Thedevice of claim 3, the adjustable mount comprising a bracket.
 5. Thedevice of claim 1, comprising a tamper that traps the sheet end afterflipping.
 6. The device of claim 1, the sheet holder comprising asurface, and further comprising a tamper that traps the sheet end afterflipping, the tamper comprising a tamper shaft, a tamper arm mounted tothe tamper shaft that engages the sheet end, and a cam arm mounted tothe tamper shaft that interacts with the cam.
 7. The device of claim 1,the blowing source comprising a tube perforated with an array of holes.8. The device of claim 1, the rotary sheet flipper being rotatable aboutan axis of rotation, the blowing source comprising a tube with alongitudinal axis parallel to the axis of rotation and perforated withan array of holes.
 9. The device of claim 8, the tube comprising anadjustable mount that permits re-orientating the tube.
 10. A sheetflipping method, comprising: receiving an end of the sheet; flipping theend with the sheet otherwise unrestrained; and blowing the sheet toassist flipping the sheet.
 11. The method of claim 10, comprisingplacing the sheet on a stack of sheets.
 12. The method of claim 10,comprising orienting and re-orientating the blowing.
 13. The method ofclaim 10, comprising trapping the sheet end after flipping.
 14. Themethod of claim 10, comprising placing the sheet on a stack of sheetsand trapping the sheet end on the stack of sheets after flipping. 15.The method of claim 10, comprising blowing the sheet with a blowingsource and orienting the blowing source.
 16. The method of claim 10,comprising blowing the sheet with a blowing source and orienting theblowing source by moving it in a first direction, a second direction,and at least a third direction.
 17. The method of claim 10, comprisingblowing the sheet with a blowing source and orienting the blowing sourceby rotating it.
 18. The method of claim 10, comprising blowing the sheetwith a blowing source and orienting the blowing source by translating itand rotating it.
 19. A sheet flipping method, comprising: receiving anend of the sheet in a rotary sheet flipper; flipping the end of thesheet with the sheet otherwise unrestrained by rotating the sheetflipper about an axis of rotation; and blowing the sheet with a blowingsource to assist flipping the sheet, the blowing source comprising atube with a longitudinal axis parallel to the axis of rotation andperforated with an array of holes.
 20. The method of claim 19,comprising placing the sheet on a stack of sheets, the array of holesbeing deflected toward the stack of sheets.